Thermal postcombustion devices are used as standard in industry for exhaust air afterburning. At the same time, they are used for obtaining thermal energy which is contained in the pollutants carried by the exhaust air.
With known thermal postcombustion devices of the aforementioned type, only a limited disposal of air containing adherent residues is possible, as deposits form on the colder regions of the heat exchanger surfaces which, over a period of time, block up the heat exchanger or at least reduce the efficiency thereof. Shutting down the operation and costly cleaning operations are, therefore, required at regular time intervals.